Neuraxial blocks and spinal haematoma: Review of 166 cases published 1994 – 2015. Part 2: diagnosis, treatment, and outcome

2.1 Severity of spinal haematoma

The severity of the initial and most serious symptoms and signs from the spinal haematoma was indicated by a four-graded scale according to Domenicucci et al [8]:

1. symptoms and signs were only somato-sensory (back pain, localized or radiating, paraesthesia, decreased sensibility) and/or sphincter deficits,

2. paresis,

3. paralysis (complete motor deficits).

Grade 0 indicates that none of the above symptoms or signs was present.

2.2 Grading of outcome of patients with SH after CNB

The outcome in patients with motor deficits was graded in four classes:

• complete recovery indicates that the motor function returned to the same level as before the CNB,

• good recovery indicates the motor function did not quite return to the pre-CNB level, but the patient was only marginally disabled and could resume normal, daily activities,

• partial recovery indicates that the patient was moderately disabled (e.g. could walk with crutches or walker),

• poor recovery indicates that there was no significant return of motor function (patient bed ridden or wheel chair dependent).

• patients who died within 30 days of the procedure were referred to as dead.

In patients with grade I, recovery was classified as complete, partial, or poor (= pain was not improved or even worsened, or incontinence persisted).

Favourable outcomes were complete or good recoveries; otherwise outcomes were referred to as unfavourable.

2.3 Statistics

Differences between study groups (first half vs. second half of the years between 1994 and 2015, outcomes in various groups) were analysed with the Chi square test, or Fischer’s exact test. A P < 0.05 indicated statistical significance.

3.1 Timing

Times from the procedure or, when appropriate, catheter removal or manipulation to the first symptom or sign of a SH are shown in Fig. 1 (4 cases with Grade 0 excluded). In 70 cases (44%), symptoms/signs started in less than 24 hours and in another 44 cases (28%) within 24-72 h. In 12 cases (7.6%) the delay was over 1 week, in 1 case as much as 3 months. In 65 cases, symptoms started after removal of the catheter. Based on the length of catheterization time, together with the proximity between removal and presenting signs, it is reasonable to assume that in 25 of these (38%) the haematoma was caused by the removal. Also, manipulations (withdrawal 1-2 cm) of catheters in situ caused 2 haematomas.

Fig. 1

Interval between CNB procedure or catheter removal and first sign of spinalhaematoma (Grade 0 excluded). See Section 3.1 for further explanation. The questionmark indicates inconclusive cases.

3.2 Symptoms and signs of the spinal haematoma (Table 1)

Initial and most severe symptoms are listed in Table 1. Pain/incontinence was the presenting sign in 81 patients, a majority of whom had back pain. In 50 of them (62%), symptoms progressed into grade II (24 cases) or grade III (26 cases) (Table 1). Motor deficits were seen in 81 cases, 60 grade II and 21 grade III. Of those initially in grade II, symptoms progressed to grade III in 19 cases (32%). In 4 cases, initial symptoms were uncharacteristic. One of these eventually developed into paralysis (grade III), a 73 y old woman with initial signs of meningeal irritation, which 12 days later evolved into paraplegia. A subdural haematoma was surgically evacuated, but the patient remained paraplegic [9].

Pain (grade I) as the final symptom was more common in patients with a subarachnoid haematoma (57%) than in patients with subdural or epidural haematomas (17%) (P < 0.001).

3.3 Diagnosis of spinal haematoma

The diagnosis was confirmed with magnetic resonance imaging (MRI) in 144 cases, computer tomography (CT) scan in 18 cases (of which 3 with a CT-myelography) and with plain myelography in 3 cases. In 3 cases, 2 because of metallic implants and 1 because of overweight, MRI was impossible. In one case [11] no radiologic examination was made.

3.4 Location of the haematoma (Table 2)

The haematoma was located epidurally in 121 patients, of whom 100 (83%) had motor deficits, subdurally in 31 (26 or 84%, with motor deficits), and subarachnoidally in 14 cases (5, or 38% with motor deficits). Six of the subdural haematomas also had some blood subarachniodally. Eight of the subdural, and 2 of the subarachnoid haematomas occurred after epidural blocks. In only one of these 10 cases were any signs of an accidental dural puncture in connection with the procedure reported. Among the spinal blocks, 10 haematomas were subarachnoid, 20 subdural (one with a simultaneous intracranial subarachnoid haematoma [13]), and 15 epidural. In the CSE group, there were 1 subarachnoid, 3 subdural, and 11 epidural haematomas (Table 2).

3.5 Treatment and outcome

Laminectomy and evacuation of the haematoma was carried out in 119 patients, while 47 were treated conservatively. Surgical treatment was carried out in 37% of grade I patients, and in 83 and 82% respectively in patients with grade II and III.

The reasons to refrain from surgical evacuation varied: most important was the severity of symptoms. None of the patients with grade 0 [10,11,12] underwent surgical evacuation of the haematoma. In 3 cases, the reason was too longstanding symptoms (surgical evacuation was considered to be of questionable benefits).

Five patients were excluded from outcome analysis: 3 patients with grade 0 [10,11,12], 1 patient with a simultaneous intracranial haemorrhage [13], and 1 patient with longstanding paraparesis because of a multiple sclerosis, who became paralytic [14]. Thus, outcomes were analysed in 161 cases: 30 with grade I, 65 with grade II, and 66 with grade III.

A favourable outcome (complete or good recovery) was seen in 83% of the patients with grade I, in 49% of those with grade II, and in 42% with grade III (P < 0.001 between grade I and grades II–III, P = 0.43 between grade II and grade III).

4.1 Diagnosis

Eighty-one cases reported from 2005 to 2015 (96%) were diagnosed with MRI, 2 cases with CT-scan, 1 of these because of contraindication to MRI (pacemaker) [17], and 1 case with myelography, the case occurred in 1977 [18]. Only 77% were examined with MRI during the first 11 years (1994-2004). Today, MRI is undoubtedly the investigation of choice for verifying and localising a post-CNB spinal haematoma.

4.2 Outcomes

The outcomes were divided into several subgroups: with regard to gravest symptom or sign of the haematoma, with regard to location of the haematoma in relation to the meninges, and with regard to the treatment of the haematoma. Surgically treated patients were compared with regard to the time lapse from the presenting neurological symptom to laminectomy: less than 12 h, 12-24 h, and more than 24 h. The 12 h interval was chosen for several reasons. Firstly, in many clinical settings (e.g. small rural hospitals far from nearest neurosurgical clinic) a shorter interval does not seem realistic to achieve in all cases [19] secondly, this choice is supported by several neurosurgical studies [8,20,2122]. Thirdly, we compared patients operated eihin 8 h with those operated 8-12 h after first sign of motor dysfunction, and found no difference in outcome.

4.2.1 Patients without motor deficits (grade I, Table 3)

In patients with grade I symptoms (mostly back pain), surgical evacuation did not seem to improve outcomes. In the non-operated group 95% were completely recovered, vs. 64% after surgical decompression. A wait-and-see approach, with meticulous follow up, seems to be the best option in patients without motor deficits.

4.2.2 Patients with motor deficits (grade II-III, paresis or paraplegia, Table 4a)

In patients with grade II-III (motor deficits), decompressing laminectomy within 12 hours resulted in the best surgical outcome in the present as well as in several other studies [e.g. 8, 20,21,22] (Table 4a). There were 50% favourable outcomes in this group, compared with 26% in those operated after more than 12 h.

Of special interest however, are the good results in the group with late laminectomy (>24 h), with 44% favourable outcomes, which compared well with the group < 12 h (50%), and superior to the group 12-24 h (5.3%, Table 4a). In 5 of the 6 cases with complete neurological recovery among those operated after 12 h [16,23,24,25,26], laminectomies were performed 24-96 h after the first sign. These results indicate that it is not justified to refrain from decompressive laminectomy because of longstanding symptoms alone. Therefore the view that there is a certain time limit from development of neurologic symptoms until surgical intervention (sometimes given as 8 h) after which complete neurological recovery is unlikely [e.g. 27,28,29] does not seem accurate. Such time limits are too pessimistic. Three patients in this review were denied surgical evacuation of their haematoma because of such a defeatist strategy. Two of them recovered completely (see below), while one died.

Several authors claim that surgery is the only effective treatment of patients suffering from a spinal haematoma with motor deficits [e.g. 4,5,6,20,30,31]. However, the present review clearly shows that this may not always be true, since outcomes of patients among those who were treated conservatively compared excellent with those operated within 12 h; favourable outcomes occurred in 18 of 23 (78%) in the non-surgical group vs. 27/54 (50%) among those laminectomized within 12 h (Table 4a). Indeed, this is not surprising, since the reason to refrain from surgical evacuation was often that neurological symptoms had stabilized (2 cases) or were resolving (10 cases), of which all made complete recoveries. Eight patients were denied surgery since an operation would be of questionable benefits, either because of long standing symptoms or poor medical condition, still 5 of them recovered completely. One of these was a 90-year old woman with gastric cancer, who developed an epidural haematoma after having a thoracic epidural catheter inserted for gastrectomy [28]. More than 12 h had elapsed from start of symptoms (paraparesis) until diagnosis, and the patient was treated conservatively since operation was considered having questionable benefits because of this delay, and also because of her age and malignancy. Her recovery was still poor after 15 days, was partial after 30 days, but was complete after 56 days.

If surgical evacuation is not indicated, the patient must be monitored carefully for any sign of progressing symptoms, and offered alternative treatment, e.g. physiotherapy. One interesting option is hyperbaric oxygen (HBO) therapy. One patient with grade II (weakness of the legs) was treated with HBO while waiting for surgical evacuation of a lumbar SEDH [32]. During this first HBO session prompt relief of the symptoms occurred, why operation was cancelled. Instead, the patient received four additional HBO sessions the following days, leading to a complete recovery. One month later, a follow up MRI demonstrated complete absorption of the haematoma.

4.2.3 Spinal subdural haematomas (Table 4c)

Of special interest are also the many unfavourable outcomes, reported in patients who underwent surgical evacuation of their spinal subdural haematomas (SSDH) (96%). Only one patient (4.2%) had a favourable outcome (Table 4c, Fig. 2). In comparison, 49% in the SEDH group had favourable outcomes (P < 0.001) (Table 4b, Fig. 2).

Fig. 2

Favourable outcomes after surgical evacuation of the haematoma in per cent of patients undergoing decompressive laminectomy for spinal epidural (left bar;N = 80) or subdural (right bar; N = 24) haematoma. Only 1 patient among those with a spinal subdural haematoma had a favourable outcome (complete recovery). See Section 4.2.3 for further explanation.

In 18 patients with SSDH (75%), of whom 2 died, surgical evacuation resulted in no significant improvement at all, while 5 patients had partial recoveries. The timing of surgery was unimportant. Eleven patients had surgery within 12 h, 7 of those had poor outcomes, 2 died, and 2 did recover partially. Three additional patients made partial recoveries, 1 of them was laminectomized after more than 30 h. The only patient in whom surgery resulted in a favourable outcome (complete recovery) complained of back pain immediately postoperatively, was discharged but returned to the hospital 2 weeks later with persistent pain, and also incontinence and leg weakness since 24 h [16]. Thus, operation took place > 24 h after first neurologic symptom. Two patients were treated conservatively, 1 grade II [33] and 1 grade III [34]; both made complete recoveries. These figures may cast a shadow of doubt as to the beneficial effects of surgical evacuation in patients suffering from a spinal subdural haematoma, even if symptoms and signs have developed into severe neurologic deficits. It must be emphasized however, that this notion is only valid for CNB cases. Yang et al [35] analysed 106 cases of non-traumatic SSDH. Of the 59 cases that were treated surgically, 42% had favourable outcomes, compared with 43% in the non-surgical group (47 cases) [35]. The reason for the poor surgical prognosis in patients with a post-CNB subdural haematoma is unclear. The motor deficits were not worse compared with those with a spinal epidural haematoma, 42% complete deficits in both groups. Regardless of location, whenever a spinal haematoma is suspected, an urgent neurosurgical consultation is mandatory.

4.3 Better outcome of post CNB spinal haematoma after 1994 (Table 5)

Overall, the outcomes after post-CNB SH among the present case reports differ from previous reviews [4,5,6] (Table 5). In particular, the mortality rate is much lower (3.7 vs. 26-28%), and the prevalence of complete recoveries is higher (45 vs. 20-22%). Possible explanations are improvements in diagnostic and therapeutic tools. E.g. among the present cases, MRI was used in 89%, while the corresponding figure reported by Vandermeulen et al [5] was 10%.

Outcomes were also improving during the study period. In the first half (1994-2004), 36% of the patients recovered completely, and 41% hade favourable outcomes. During the second half (2005-2015) the corresponding figures were 54% and 64% respectively (P = 0.004). Even here, improved diagnostic tools may explain the better outcomes. In the first period, MRI was used in 77% of the cases, during the second period it was used in 96%.